Attachment for mortise machines



April 13, 1948.V D, N, BRQWN 2,439,558

ATTACHMENT FOR MORTISE MACHINES v FileqJan. 3, 1944 V2 sneets-sn`eet 1 April 13, 194s. DfN. BROWN 2,439,558 y ATTACHMENTFOR MoRTIsE MACHINES A Filed Jan. 3, 1944 2 sheets-snelst 2 #.lig f- I I l v l I Hlllmmwf @L Patented pr. 13, 1948 UNITED-*STATES PATENT oFFIcE l v 2,439,558 ATrAcHMEN'rFoR Mon'rlsnMACHINES` lloyes N. Brown, Vallejo, Calif. I Appliation January 3, 1944, seriaiNo. 516,811

This invention relates tomortise machines and more particularly to the improvement of a mortise machine to enlarge its usefulness, the amount and character of the work that can be done, and the saving of time in the performance of such work.

Mortise machines are `operated with a single hollow chisel and bit fastened respectively to the solid and rotary parts of the head. With this type of construction a large number of cuts are necessary to make the desiredmortise which apparently is out of keeping with the times when the saving of time, labor and material is so vitally important. 1'

It is an object of the invention to improve a mortise machine by providing'an attachment by means of which a mortise of a length corresponding to several chisel diameters can be quickly and accurately made with the fewest operations.

The invention .contemplates an attachment carrying several hollow chisels'and bits arranged in alignment to cut in a single operation a row of holes with separating portions which may be removed by a second single cutting operation to complete the mortise. The hollow chisels are supported in the body of the attachment and gearing is provided in the body for driving the bits in a rotary manner from the head of the conventional machine to which the attachment is applied.

The foregoing and other objects and advantages will become apparent in view of the foregoing description taken in conjunction with the drawings, wherein:

Figure 1 is a front View partly in elevation and partly in section disclosing the driving mechanism for the bits;

Fig. 2, a central vertical section at right angles to that of Fig. 1;

Fig. 3, a horizontal section on an enlarged scale illustrating the structure for driving the four bits;

Fig. 4, a piece of material after a single operation of a mortise machine with the attachment of the present invention employing four bits; and

Fig. 5, a view on an enlarged scale of a piece of work which has received two cutting operations of a mortise machine with the attachment of the present invention but with three long and one short hollow chisels and bits in order to form a relish.

Referring to the drawings the conventional mortise machine employs a structure for imparting rotary motion to a bit and permitting Vaxial movement or reciprocating motion to a chisel of 1 Claim.` (Cl. 144-78) square cross section so that a hole may be drilled and its corners squared by endwise or axial movement of the chisel. l

The rotary portion` I0 of the conventional head has therein a `cylindrical socket 8 which receives a split collar 9 held in the socket by a threaded ring nut 1. The rotary portion has a set screw I 2 which serves to hold the shaft I3 of the attachment of the present invention in place. This `shaft has a flat surface 6 which is engaged by the set screw I2, such engagement being sufficiently loose to permit the drive shaft I3 to reciprocate or move axially within its socket.

The shaft I3 hasits lower end disposedin a cylindrioal'boss I5 extending upwardly from the body I4. The cylindricalv boss I5 surrounds the lower end of the shaft I 3 and in turn is adapted to be engaged by the solid or reciprocating part of the head .(not shown) of the mortise machine. The shaft I3 corresponds to the shank of the usual single bit enclosed by a single hollow chisel. In the present attachment the shaft I3 is utilized to drive a multiplicity or plurality of bits each having a hollow chisel by means of gears including a gear I6 fixed to the lower end of theshaft I3 as shown in Figs. 2 and 3.

The gear I6 on the lower end of the shaft I3 drives a pair of identical idler gears I1 which in turn drive four identical driven gears I8, each gear I1 driving two gears I8. The gears I 8 are provided with sockets I9 in their lower portions and set screws 20. The upper ends of drill. bits 2l iit into the sockets I9 in the gears I8 and are securely fastened therein by means of the set screws 20. The body I4 is provided with a window 22 .with a closure 23 held in place by a set screw 24 through which window access to the set screws 20 may be had for removing or replacing one or more of the bits 2|.

In the bottom of the body I4 there is a plurality of sockets 25 with set screws 26, in which sockets are held by the set screws, chisels 21 having cutting extremities 28 at their lower ends and elongated apertures 29 at approximately their mid sections through which shavings may escape.

An oiler 30 may be employed for supplying lubricant to the rotating parts by means of channels 3| and 32; the ,channels terminating above the upper ends of each of the gears I8 journalled in the body I4.

The conventional mortise machine is built to accommodate a range of sizes of hollow chisels and bits. As previously stated, in the attachments of this invention the cylindrical boss I5 in the body I4 is adapted to t in the solid or reciprocating part of the head. The split collars which are used over the shanks of the individual chisels and inside the socket in the solid or reciprocating part of the head are used to t around the cylindrical abutment I5 on the attachment of the present invention. The same is true of the rotary part of the head which drives the single drill bit in the conventinal mortise machine wherein split collars 9 are used to hold in place and drive the single drillbit. The same split collars 9 are used in the socket 8 of the rotary part of the head to hold in place and drive the shaft I'3 of the attach'- any number of them may be used. 'T iikewise'by the utilization of a short hollow chisel and bit aty 4 for operative connection to said machine; a plurality of spaced apart hollow chisel sockets in the bottom wall of said housing; a plurality of hollow chisels removably secured in said chisel sockets; a plurality of spaced apart driven gear elements journalled in said housing and disposed one in axial alignment with each lof said chisel sockets and having their axes disposed substantially in a common plane; a bit receiving socket in each of said driven gear elements, a bit operatively associated with each of said hollow chisels and removably secured in said bit receiving socket; a pair of idler gears journalled in said housing,

A'each meshingwith :one-half of said plurality of driven gear elements; a drive gear disposed between and meshing with said idler gears, said idler gears andV said drive gear having theiraxes one end of the device a mortise can be made with a relish in two cutting operations. For instance by using one short chisel bit in conjunction with several lon-g ones, and by making two cuts, a mortise 36 with a relish 31 may be made in the material 34, as shown in Fig. 5.

With the device as shown in Fig. 1 four cuts 33 may be made Yin material 34 in one operation and with a second operation the material between the four cuts may be removed as well as an additional cut made thereby making the length of the cut out mortise eight times that cut by a single hollow chisel. v

It will be obvious to those skilled in the art that various changes in the invention may be made without departing from the spirit and scope thereof, ,and the invention is not limited to that described in the specification and shown in the drawing but only as set forth in the appended claim. f

What is claimed is:

In a multiple bit attachment for a conventional single bit mortising machine, a housing arranged substantiallyin a common plane parallel Yto the planeof the axes of said driven gear elements and said idler gears being larger than said drive gear by an amount sufficient to permit meshing of said drive gear'with said idler gears without interference with said driven gear elements; and a drive shaft extending from said drive :gear out of said housing for operative connection'to the machine.

DOYESJN. BROWN.

REFERENCES CITED The following references are of record in the le of this patent:V

UNrTED STATES PATENTS 

